BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Lusztig's unipotent pieces and geometric invariant theory - Matthe
 w Clarke (Cambridge)
DTSTART:20110311T140000Z
DTEND:20110311T150000Z
UID:TALK29637@talks.cam.ac.uk
CONTACT:Chris Bowman
DESCRIPTION:Linear algebraic groups are subgroups of the general linear gr
 oup which are closed under the Zariski topology. The concept is similar to
  that of Lie groups\, although fields of prime characteristic are admitted
 \, and indeed arguably provide the most interesting problems and applicati
 ons. A very important class of linear algebraic groups are reductive group
 s\, which include all the classical groups. This talk is concerned with th
 e conjugacy classes of unipotent elements in a reductive group\, i.e. the 
 matrices which have all eigenvalues all equal to 1. These classes are very
  important in many topics and we have a nice classification of them when t
 he characteristic of the field is not too small. When it is too small thin
 gs can get a bit ugly\, but a unified geometric picture has been proposed 
 by G. Lusztig in a series of conjectures\, some of which he proved in a ca
 se-by-case manner. In this talk I will explain a uniform approach to these
  conjectures using geometric invariant theory\, which has yielded a short 
 case-free proof. This is joint work with Professor A. Premet (Manchester).
  
LOCATION:MR4
END:VEVENT
END:VCALENDAR